First off, I believe that the 49ers would be content with "renting" him for $6m in 2013. If he wants to make a reasonable deal after '13, fine. If he wants to be the highest paid defensive player, so long.
we are in our "super bowl window" for the next 5 years. And the addition of Revis in 2013 would significantly improve our chances on 2013 (let's say of repeating).
We would have the deepest secondary in history, assuming Goldson resigns. Cully would be at dime...or rotate w Brown and Rogers, depending who is the best matchup. The competition for playing Time would be something to behold as well.
Brown is also a free agent after 2013. We resign one of them.
Our secondary has been very lucky with injuries over the past few years...how long will that last?
trade proposition: Alex Smith, a 4th, and a 5th.